21041047 has 2 divisors, whose sum is σ = 21041048. Its totient is φ = 21041046.

The previous prime is 21041029. The next prime is 21041071. The reversal of 21041047 is 74014012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21041047 - 2⁷ = 21040919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21041747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520523 + 10520524.

It is an arithmetic number, because the mean of its divisors is an integer number (10520524).

Almost surely, 2^21041047 is an apocalyptic number.

21041047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21041047 is an equidigital number, since it uses as much as digits as its factorization.

21041047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 21041047 is about 4587.0521034756. The cubic root of 21041047 is about 276.0720555059.

Adding to 21041047 its reverse (74014012), we get a palindrome (95055059).

The spelling of 21041047 in words is "twenty-one million, forty-one thousand, forty-seven".